Surgical robotic automation with tracking markers and controlled tool advancement

ABSTRACT

Devices, systems, and methods for aiding insertion of a surgical implant by providing a threaded guide tube configured to engage a threaded surgical instrument such that an end-effector of a robot may provide force to drive the surgical implant into a patient. In addition, devices, systems, and methods relating to a dilator system for use with a robotic system that allows independent and separate control of tools within the dilator system.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 15/609,334, filed May 31, 2017 (published as U.S. PatentPublication No. 2017/0258535), which is a continuation-in-part of U.S.patent application Ser. No. 15/157,444, filed May 18, 2016 (published asU.S. Patent Publication No. 2016-0256225), which is acontinuation-in-part of U.S. patent application Ser. No. 15/095,883,filed Apr. 11, 2016 (published as U.S. Patent Publication No.2016-0220320), which is a continuation-in-part of U.S. patentapplication Ser. No. 14/062,707, filed on Oct. 24, 2013 (published asU.S. Patent Publication No. 2014-0275955), which is acontinuation-in-part application of U.S. patent application Ser. No.13/924,505, filed on Jun. 21, 2013 (now U.S. Pat. No. 9,782,229), whichclaims priority to provisional application No. 61/662,702 filed on Jun.21, 2012 (expired) and claims priority to provisional application No.61/800,527 filed on Mar. 15, 2013 (expired), all of which areincorporated by reference herein in their entireties for all purposes.

FIELD

The present disclosure relates to position recognition systems, and inparticular, end-effector and tool tracking and manipulation during arobot assisted surgery.

BACKGROUND

Various medical procedures require the accurate localization of athree-dimensional (3D) position of a surgical instrument within the bodyin order to effect optimized treatment. For example, some surgicalprocedures to fuse vertebrae require that a surgeon drill multiple holesinto the bone structure at specific locations. To achieve high levels ofmechanical integrity in the fusing system, and to balance the forcescreated in the bone structure, it is necessary that the holes aredrilled at the correct location. Vertebrae, like most bone structures,have complex shapes including non-planar curved surfaces making accurateand perpendicular drilling difficult.

Conventionally, using currently-available systems and methods, a surgeonmanually holds and positions a drill guide tube by using a guidancesystem to overlay the drill tube's position onto a three-dimensionalimage of the anatomical structures of a patient, for example, bonestructures of the patient. This manual process is both tedious, timeconsuming, and error-prone. Further, whether the surgery can beconsidered successful largely depends upon the dexterity of the surgeonwho performs it. Thus, there is a need for the use of robot assistedsurgery to more accurately position surgical instruments and moreaccurately depict the position of those instruments in relation to theanatomical structures of the patient.

Currently, limited robotic assistance for surgical procedures isavailable. For example, certain systems allow a user to control arobotic actuator. These systems convert a surgeon's gross movements intomicro-movements of the robotic actuator to more accurately position andsteady the surgical instruments when undergoing surgery. Although thesesystems may aid in eliminating hand tremor and provide the surgeon withimproved ability to work through a small opening, like many of therobots commercially available today, these systems are expensive,obtrusive, and require a cumbersome setup for the robot in relation tothe patient and the user (e.g., a surgeon). Further, for certainprocedures, such as thoracolumbar pedicle screw insertion, theseconventional methods are known to be error-prone and tedious.

The current systems have many drawbacks including but not limited to thefact that autonomous movement and precise placement of a surgicalinstrument can be hindered by a lack of mechanical feedback and/or aloss of visual placement once the instrument is submerged within aportion of a patient. These drawbacks make the existing surgicalapplications error prone resulting in safety hazards to the patient aswell as the surgeon during surgical procedures.

In addition, current robot assisted systems suffer from otherdisadvantages. The path and angle in which a surgical instrument isinserted into a patient (a trajectory of the instrument) may be limiteddue to the configuration of the robot arm and the manner in which it canmove. For example, some current systems may not have enough range ofmotion or movement to place the surgical instrument at a trajectoryideal for placement into the patient and/or at a position that allowsthe surgeon an optimal view for performing the surgery.

The present disclosure overcomes the disadvantages of current robotassisted surgical applications. For example, the present disclosureallows for precisely locating anatomical structures in open,percutaneous, or minimally invasive surgery (MIS) procedures andpositioning surgical instruments or implants during surgery. Inaddition, the present disclosure may improve stereotactic surgicalprocedures by allowing for identification and reference to a rigidanatomical structure relative to a pre-op computerized tomography (CT)scan, intra-operative CT scan, or fluoroscopy/X-ray based image of theanatomy. Further, the present disclosure may integrate a surgicalrobotic arm with an end-effector, a local positioning system, a dynamicreference base, and planning software to assist a surgeon in performingmedical procedures in a more accurate and safe manner thereby reducingthe error prone characteristics of current robot assisted systems andmethods.

In addition, to overcome other disadvantages of current robot assistedsurgical applications, an objective of the present disclosure is toprovide substantial driving power using the robotic arm and theend-effector to surgical tools, such as screws and other tools. This maybe accomplished by matching internal threads on the end-effector andexternal threads on the surgical tool. Using the interlocking power ofthe threads allows the end-effector to assist in driving the tools intohard tissues such as bone during operation.

Moreover, to overcome other disadvantages of current robot assistedsurgical applications, an objective of the present disclosure is toprovide separate fine control of two or more components of a surgicaltool, such as a dilator, by utilizing concentric mount points that canattach to the same drill. With these independent controls, the surgeoncan force down or retract one portion of a tool without affecting theposition of a second portion of the tool, and vice versa.

SUMMARY

To meet this and other needs, devices, systems, and methods the presentdisclosure provides a surgical robot system that includes a robot havinga robot base, a robot arm coupled to the robot base, an end-effectorcoupled to the robot arm, a guide tube coupled to the end-effector, anda surgical instrument coupled to the guide tube. The robot may beconfigured to control movement of the end-effector to perform a givensurgical procedure, the guide tube may have internal threading and thesurgical instrument may have external threading configured to engage theinternal threading, and the surgical instrument may be configured toengage a surgical implant while threadably engaged with the guide tube.

The present disclosure also provides a dilator system for a surgicalrobot that includes an outer sleeve, a center shank at least partiallydisposed within the outer sleeve, a rod at least partially disposedwithin the outer sleeve, an outer dilator disposed within the outersleeve, an inner dilator disposed within the outer dilator. The centershank may be configured to advance a center pin into a bone, the rod maybe configured to advance the inner dilator over the center pin, and theouter dilator may be configured to advance over the inner dilator.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overhead view of a potential arrangement for locations ofthe robotic system, patient, surgeon, and other medical personnel duringa surgical procedure;

FIG. 2 illustrates the robotic system including positioning of thesurgical robot and the camera relative to the patient according to oneembodiment;

FIG. 3 illustrates a surgical robotic system in accordance with anexemplary embodiment;

FIG. 4 illustrates a portion of a surgical robot in accordance with anexemplary embodiment;

FIG. 5 illustrates a block diagram of a surgical robot in accordancewith an exemplary embodiment;

FIG. 6 illustrates a surgical robot in accordance with an exemplaryembodiment;

FIGS. 7A-7C illustrate an end-effector in accordance with an exemplaryembodiment;

FIG. 8 illustrates a surgical instrument and the end-effector, beforeand after, inserting the surgical instrument into the guide tube of theend-effector according to one embodiment;

FIGS. 9A-9C illustrate portions of an end-effector and robot arm inaccordance with an exemplary embodiment;

FIG. 10 illustrates a dynamic reference array, an imaging array, andother components in accordance with an exemplary embodiment;

FIG. 11 illustrates a method of registration in accordance with anexemplary embodiment;

FIG. 12A-12B illustrate embodiments of imaging devices according toexemplary embodiments;

FIG. 13A illustrates a portion of a robot including the robot arm and anend-effector in accordance with an exemplary embodiment;

FIG. 13B is a close-up view of the end-effector, with a plurality oftracking markers rigidly affixed thereon, shown in FIG. 13A;

FIG. 13C is a tool or instrument with a plurality of tracking markersrigidly affixed thereon according to one embodiment;

FIG. 14A is an alternative version of an end-effector with moveabletracking markers in a first configuration;

FIG. 14B is the end-effector shown in FIG. 14A with the moveabletracking markers in a second configuration;

FIG. 14C shows the template of tracking markers in the firstconfiguration from FIG. 14A;

FIG. 14D shows the template of tracking markers in the secondconfiguration from FIG. 14B;

FIG. 15A shows an alternative version of the end-effector having only asingle tracking marker affixed thereto;

FIG. 15B shows the end-effector of FIG. 15A with an instrument disposedthrough the guide tube;

FIG. 15C shows the end-effector of FIG. 15A with the instrument in twodifferent positions, and the resulting logic to determine if theinstrument is positioned within the guide tube or outside of the guidetube;

FIG. 15D shows the end-effector of FIG. 15A with the instrument in theguide tube at two different frames and its relative distance to thesingle tracking marker on the guide tube;

FIG. 15E shows the end-effector of FIG. 15A relative to a coordinatesystem;

FIG. 16 is a block diagram of a method for navigating and moving theend-effector of the robot to a desired target trajectory;

FIGS. 17A-17B depict an instrument for inserting an expandable implanthaving fixed and moveable tracking markers in contracted and expandedpositions, respectively;

FIGS. 18A-18B depict an instrument for inserting an articulating implanthaving fixed and moveable tracking markers in insertion and angledpositions, respectively;

FIGS. 19A depicts an embodiment of a robot with interchangeable oralternative end-effectors; and

FIG. 19B depicts an embodiment of a robot with an instrument styleend-effector coupled thereto.

FIG. 20 depicts a guide tube consistent with the principles of thepresent disclosure.

FIG. 21 depicts a surgical tool consistent with the principles of thepresent disclosure.

FIG. 22 depicts a dilator mechanism consistent with the principles ofthe present disclosure.

FIG. 23 depicts an advancement mechanism consistent with the principlesof the present disclosure.

FIG. 24 depicts certain components of the dilator mechanism consistentwith the principles of the present disclosure.

FIGS. 25A and 25B depict a dilator mechanism consistent with theprinciples of the present disclosure.

FIGS. 26A and 26B depict a dilator mechanism consistent with theprinciples of the present disclosure.

FIGS. 27A-D depict a dilator mechanism consistent with the principles ofthe present disclosure.

FIGS. 28A-C depict a dilator mechanism consistent with the principles ofthe present disclosure.

DETAILED DESCRIPTION

It is to be understood that the present disclosure is not limited in itsapplication to the details of construction and the arrangement ofcomponents set forth in the description herein or illustrated in thedrawings. The teachings of the present disclosure may be used andpracticed in other embodiments and practiced or carried out in variousways. Also, it is to be understood that the phraseology and terminologyused herein is for the purpose of description and should not be regardedas limiting. The use of “including,” “comprising,” or “having” andvariations thereof herein is meant to encompass the items listedthereafter and equivalents thereof as well as additional items. Unlessspecified or limited otherwise, the terms “mounted,” “connected,”“supported,” and “coupled” and variations thereof are used broadly andencompass both direct and indirect mountings, connections, supports, andcouplings. Further, “connected” and “coupled” are not restricted tophysical or mechanical connections or couplings.

The following discussion is presented to enable a person skilled in theart to make and use embodiments of the present disclosure. Variousmodifications to the illustrated embodiments will be readily apparent tothose skilled in the art, and the principles herein can be applied toother embodiments and applications without departing from embodiments ofthe present disclosure. Thus, the embodiments are not intended to belimited to embodiments shown, but are to be accorded the widest scopeconsistent with the principles and features disclosed herein. Thefollowing detailed description is to be read with reference to thefigures, in which like elements in different figures have like referencenumerals. The figures, which are not necessarily to scale, depictselected embodiments and are not intended to limit the scope of theembodiments. Skilled artisans will recognize the examples providedherein have many useful alternatives and fall within the scope of theembodiments.

Turning now to the drawing, FIGS. 1 and 2 illustrate a surgical robotsystem 100 in accordance with an exemplary embodiment. Surgical robotsystem 100 may include, for example, a surgical robot 102, one or morerobot arms 104, a base 106, a display 110, an end-effector 112, forexample, including a guide tube 114, and one or more tracking markers118. The surgical robot system 100 may include a patient tracking device116 also including one or more tracking markers 118, which is adapted tobe secured directly to the patient 210 (e.g., to the bone of the patient210). The surgical robot system 100 may also utilize a camera 200, forexample, positioned on a camera stand 202. The camera stand 202 can haveany suitable configuration to move, orient, and support the camera 200in a desired position. The camera 200 may include any suitable camera orcameras, such as one or more infrared cameras (e.g., bifocal orstereophotogrammetric cameras), able to identify, for example, activeand passive tracking markers 118 in a given measurement volume viewablefrom the perspective of the camera 200. The camera 200 may scan thegiven measurement volume and detect the light that comes from themarkers 118 in order to identify and determine the position of themarkers 118 in three-dimensions. For example, active markers 118 mayinclude infrared-emitting markers that are activated by an electricalsignal (e.g., infrared light emitting diodes (LEDs)), and passivemarkers 118 may include retro-reflective markers that reflect infraredlight (e.g., they reflect incoming IR radiation into the direction ofthe incoming light), for example, emitted by illuminators on the camera200 or other suitable device.

FIGS. 1 and 2 illustrate a potential configuration for the placement ofthe surgical robot system 100 in an operating room environment. Forexample, the robot 102 may be positioned near or next to patient 210.Although depicted near the head of the patient 210, it will beappreciated that the robot 102 can be positioned at any suitablelocation near the patient 210 depending on the area of the patient 210undergoing the operation. The camera 200 may be separated from the robotsystem 100 and positioned at the foot of patient 210. This locationallows the camera 200 to have a direct visual line of sight to thesurgical field 208. Again, it is contemplated that the camera 200 may belocated at any suitable position having line of sight to the surgicalfield 208. In the configuration shown, the surgeon 120 may be positionedacross from the robot 102, but is still able to manipulate theend-effector 112 and the display 110. A surgical assistant 126 may bepositioned across from the surgeon 120 again with access to both theend-effector 112 and the display 110. If desired, the locations of thesurgeon 120 and the assistant 126 may be reversed. The traditional areasfor the anesthesiologist 122 and the nurse or scrub tech 124 remainunimpeded by the locations of the robot 102 and camera 200.

With respect to the other components of the robot 102, the display 110can be attached to the surgical robot 102 and in other exemplaryembodiments, display 110 can be detached from surgical robot 102, eitherwithin a surgical room with the surgical robot 102, or in a remotelocation. End-effector 112 may be coupled to the robot arm 104 andcontrolled by at least one motor. In exemplary embodiments, end-effector112 can comprise a guide tube 114, which is able to receive and orient asurgical instrument 608 (described further herein) used to performsurgery on the patient 210. As used herein, the term “end-effector” isused interchangeably with the terms “end-effectuator” and “effectuatorelement.” Although generally shown with a guide tube 114, it will beappreciated that the end-effector 112 may be replaced with any suitableinstrumentation suitable for use in surgery. In some embodiments,end-effector 112 can comprise any known structure for effecting themovement of the surgical instrument 608 in a desired manner.

The surgical robot 102 is able to control the translation andorientation of the end-effector 112. The robot 102 is able to moveend-effector 112 along x-, y-, and z-axes, for example. The end-effector112 can be configured for selective rotation about one or more of thex-, y-, and z-axis , and a Z Frame axis (such that one or more of theEuler Angles (e.g., roll, pitch, and/or yaw) associated withend-effector 112 can be selectively controlled). In some exemplaryembodiments, selective control of the translation and orientation ofend-effector 112 can permit performance of medical procedures withsignificantly improved accuracy compared to conventional robots thatutilize, for example, a six degree of freedom robot arm comprising onlyrotational axes. For example, the surgical robot system 100 may be usedto operate on patient 210, and robot arm 104 can be positioned above thebody of patient 210, with end-effector 112 selectively angled relativeto the z-axis toward the body of patient 210.

In some exemplary embodiments, the position of the surgical instrument608 can be dynamically updated so that surgical robot 102 can be awareof the location of the surgical instrument 608 at all times during theprocedure. Consequently, in some exemplary embodiments, surgical robot102 can move the surgical instrument 608 to the desired position quicklywithout any further assistance from a physician (unless the physician sodesires). In some further embodiments, surgical robot 102 can beconfigured to correct the path of the surgical instrument 608 if thesurgical instrument 608 strays from the selected, preplanned trajectory.In some exemplary embodiments, surgical robot 102 can be configured topermit stoppage, modification, and/or manual control of the movement ofend-effector 112 and/or the surgical instrument 608. Thus, in use, inexemplary embodiments, a physician or other user can operate the system100, and has the option to stop, modify, or manually control theautonomous movement of end-effector 112 and/or the surgical instrument608. Further details of surgical robot system 100 including the controland movement of a surgical instrument 608 by surgical robot 102 can befound in co-pending U.S. patent application Ser. No. 13/924,505, whichis incorporated herein by reference in its entirety.

The robotic surgical system 100 can comprise one or more trackingmarkers 118 configured to track the movement of robot arm 104,end-effector 112, patient 210, and/or the surgical instrument 608 inthree dimensions. In exemplary embodiments, a plurality of trackingmarkers 118 can be mounted (or otherwise secured) thereon to an outersurface of the robot 102, such as, for example and without limitation,on base 106 of robot 102, on robot arm 104, or on the end-effector 112.In exemplary embodiments, at least one tracking marker 118 of theplurality of tracking markers 118 can be mounted or otherwise secured tothe end-effector 112. One or more tracking markers 118 can further bemounted (or otherwise secured) to the patient 210. In exemplaryembodiments, the plurality of tracking markers 118 can be positioned onthe patient 210 spaced apart from the surgical field 208 to reduce thelikelihood of being obscured by the surgeon, surgical tools, or otherparts of the robot 102. Further, one or more tracking markers 118 can befurther mounted (or otherwise secured) to the surgical tools 608 (e.g.,a screw driver, dilator, implant inserter, or the like). Thus, thetracking markers 118 enable each of the marked objects (e.g., theend-effector 112, the patient 210, and the surgical tools 608) to betracked by the robot 102. In exemplary embodiments, system 100 can usetracking information collected from each of the marked objects tocalculate the orientation and location, for example, of the end-effector112, the surgical instrument 608 (e.g., positioned in the tube 114 ofthe end-effector 112), and the relative position of the patient 210.

The markers 118 may include radiopaque or optical markers. The markers118 may be suitably shaped include spherical, spheroid, cylindrical,cube, cuboid, or the like. In exemplary embodiments, one or more ofmarkers 118 may be optical markers. In some embodiments, the positioningof one or more tracking markers 118 on end-effector 112 can maximize theaccuracy of the positional measurements by serving to check or verifythe position of end-effector 112. Further details of surgical robotsystem 100 including the control, movement and tracking of surgicalrobot 102 and of a surgical instrument 608 can be found in co-pendingU.S. patent application Ser. No. 13/924,505, which is incorporatedherein by reference in its entirety.

Exemplary embodiments include one or more markers 118 coupled to thesurgical instrument 608. In exemplary embodiments, these markers 118,for example, coupled to the patient 210 and surgical instruments 608, aswell as markers 118 coupled to the end-effector 112 of the robot 102 cancomprise conventional infrared light-emitting diodes (LEDs) or anOptotrak® diode capable of being tracked using a commercially availableinfrared optical tracking system such as Optotrak®. Optotrak® is aregistered trademark of Northern Digital Inc., Waterloo, Ontario,Canada. In other embodiments, markers 118 can comprise conventionalreflective spheres capable of being tracked using a commerciallyavailable optical tracking system such as Polaris Spectra. PolarisSpectra is also a registered trademark of Northern Digital, Inc. In anexemplary embodiment, the markers 118 coupled to the end-effector 112are active markers which comprise infrared light-emitting diodes whichmay be turned on and off, and the markers 118 coupled to the patient 210and the surgical instruments 608 comprise passive reflective spheres.

In exemplary embodiments, light emitted from and/or reflected by markers118 can be detected by camera 200 and can be used to monitor thelocation and movement of the marked objects. In alternative embodiments,markers 118 can comprise a radio-frequency and/or electromagneticreflector or transceiver and the camera 200 can include or be replacedby a radio-frequency and/or electromagnetic transceiver.

Similar to surgical robot system 100, FIG. 3 illustrates a surgicalrobot system 300 and camera stand 302, in a docked configuration,consistent with an exemplary embodiment of the present disclosure.Surgical robot system 300 may comprise a robot 301 including a display304, upper arm 306, lower arm 308, end-effector 310, vertical column312, casters 314, cabinet 316, tablet drawer 318, connector panel 320,control panel 322, and ring of information 324. Camera stand 302 maycomprise camera 326. These components are described in greater withrespect to FIG. 5. FIG. 3 illustrates the surgical robot system 300 in adocked configuration where the camera stand 302 is nested with the robot301, for example, when not in use. It will be appreciated by thoseskilled in the art that the camera 326 and robot 301 may be separatedfrom one another and positioned at any appropriate location during thesurgical procedure, for example, as shown in FIGS. 1 and 2.

FIG. 4 illustrates a base 400 consistent with an exemplary embodiment ofthe present disclosure. Base 400 may be a portion of surgical robotsystem 300 and comprise cabinet 316. Cabinet 316 may house certaincomponents of surgical robot system 300 including but not limited to abattery 402, a power distribution module 404, a platform interface boardmodule 406, a computer 408, a handle 412, and a tablet drawer 414. Theconnections and relationship between these components is described ingreater detail with respect to FIG. 5.

FIG. 5 illustrates a block diagram of certain components of an exemplaryembodiment of surgical robot system 300. Surgical robot system 300 maycomprise platform subsystem 502, computer subsystem 504, motion controlsubsystem 506, and tracking subsystem 532. Platform subsystem 502 mayfurther comprise battery 402, power distribution module 404, platforminterface board module 406, and tablet charging station 534. Computersubsystem 504 may further comprise computer 408, display 304, andspeaker 536. Motion control subsystem 506 may further comprise drivercircuit 508, motors 510, 512, 514, 516, 518, stabilizers 520, 522, 524,526, end-effector 310, and controller 538. Tracking subsystem 532 mayfurther comprise position sensor 540 and camera converter 542. System300 may also comprise a foot pedal 544 and tablet 546.

Input power is supplied to system 300 via a power source 548 which maybe provided to power distribution module 404. Power distribution module404 receives input power and is configured to generate different powersupply voltages that are provided to other modules, components, andsubsystems of system 300. Power distribution module 404 may beconfigured to provide different voltage supplies to platform interfacemodule 406, which may be provided to other components such as computer408, display 304, speaker 536, driver 508 to, for example, power motors512, 514, 516, 518 and end-effector 310, motor 510, ring 324, cameraconverter 542, and other components for system 300 for example, fans forcooling the electrical components within cabinet 316.

Power distribution module 404 may also provide power to other componentssuch as tablet charging station 534 that may be located within tabletdrawer 318. Tablet charging station 534 may be in wireless or wiredcommunication with tablet 546 for charging table 546. Tablet 546 may beused by a surgeon consistent with the present disclosure and describedherein.

Power distribution module 404 may also be connected to battery 402,which serves as temporary power source in the event that powerdistribution module 404 does not receive power from input power 548. Atother times, power distribution module 404 may serve to charge battery402 if necessary.

Other components of platform subsystem 502 may also include connectorpanel 320, control panel 322, and ring 324. Connector panel 320 mayserve to connect different devices and components to system 300 and/orassociated components and modules. Connector panel 320 may contain oneor more ports that receive lines or connections from differentcomponents. For example, connector panel 320 may have a ground terminalport that may ground system 300 to other equipment, a port to connectfoot pedal 544 to system 300, a port to connect to tracking subsystem532, which may comprise position sensor 540, camera converter 542, andcameras 326 associated with camera stand 302. Connector panel 320 mayalso include other ports to allow USB, Ethernet, HDMI communications toother components, such as computer 408.

Control panel 322 may provide various buttons or indicators that controloperation of system 300 and/or provide information regarding system 300.For example, control panel 322 may include buttons to power on or offsystem 300, lift or lower vertical column 312, and lift or lowerstabilizers 520-526 that may be designed to engage casters 314 to locksystem 300 from physically moving. Other buttons may stop system 300 inthe event of an emergency, which may remove all motor power and applymechanical brakes to stop all motion from occurring. Control panel 322may also have indicators notifying the user of certain system conditionssuch as a line power indicator or status of charge for battery 402.

Ring 324 may be a visual indicator to notify the user of system 300 ofdifferent modes that system 300 is operating under and certain warningsto the user.

Computer subsystem 504 includes computer 408, display 304, and speaker536. Computer 504 includes an operating system and software to operatesystem 300. Computer 504 may receive and process information from othercomponents (for example, tracking subsystem 532, platform subsystem 502,and/or motion control subsystem 506) in order to display information tothe user. Further, computer subsystem 504 may also include speaker 536to provide audio to the user.

Tracking subsystem 532 may include position sensor 504 and converter542. Tracking subsystem 532 may correspond to camera stand 302 includingcamera 326 as described with respect to FIG. 3. Position sensor 504 maybe camera 326. Tracking subsystem may track the location of certainmarkers that are located on the different components of system 300and/or instruments used by a user during a surgical procedure. Thistracking may be conducted in a manner consistent with the presentdisclosure including the use of infrared technology that tracks thelocation of active or passive elements, such as LEDs or reflectivemarkers, respectively. The location, orientation, and position ofstructures having these types of markers may be provided to computer 408which may be shown to a user on display 304. For example, a surgicalinstrument 608 having these types of markers and tracked in this manner(which may be referred to as a navigational space) may be shown to auser in relation to a three dimensional image of a patient's anatomicalstructure.

Motion control subsystem 506 may be configured to physically movevertical column 312, upper arm 306, lower arm 308, or rotateend-effector 310. The physical movement may be conducted through the useof one or more motors 510-518. For example, motor 510 may be configuredto vertically lift or lower vertical column 312. Motor 512 may beconfigured to laterally move upper arm 308 around a point of engagementwith vertical column 312 as shown in FIG. 3. Motor 514 may be configuredto laterally move lower arm 308 around a point of engagement with upperarm 308 as shown in FIG. 3. Motors 516 and 518 may be configured to moveend-effector 310 in a manner such that one may control the roll and onemay control the tilt, thereby providing multiple angles thatend-effector 310 may be moved. These movements may be achieved bycontroller 538 which may control these movements through load cellsdisposed on end-effector 310 and activated by a user engaging these loadcells to move system 300 in a desired manner.

Moreover, system 300 may provide for automatic movement of verticalcolumn 312, upper arm 306, and lower arm 308 through a user indicatingon display 304 (which may be a touchscreen input device) the location ofa surgical instrument or component on three dimensional image of thepatient's anatomy on display 304. The user may initiate this automaticmovement by stepping on foot pedal 544 or some other input means.

FIG. 6 illustrates a surgical robot system 600 consistent with anexemplary embodiment. Surgical robot system 600 may compriseend-effector 602, robot arm 604, guide tube 606, instrument 608, androbot base 610. Instrument tool 608 may be attached to a tracking array612 including one or more tracking markers (such as markers 118) andhave an associated trajectory 614. Trajectory 614 may represent a pathof movement that instrument tool 608 is configured to travel once it ispositioned through or secured in guide tube 606, for example, a path ofinsertion of instrument tool 608 into a patient. In an exemplaryoperation, robot base 610 may be configured to be in electroniccommunication with robot arm 604 and end-effector 602 so that surgicalrobot system 600 may assist a user (for example, a surgeon) in operatingon the patient 210. Surgical robot system 600 may be consistent withpreviously described surgical robot system 100 and 300.

A tracking array 612 may be mounted on instrument 608 to monitor thelocation and orientation of instrument tool 608. The tracking array 612may be attached to an instrument 608 and may comprise tracking markers804. As best seen in FIG. 8, tracking markers 804 may be, for example,light emitting diodes and/or other types of reflective markers (e.g.,markers 118 as described elsewhere herein). The tracking devices may beone or more line of sight devices associated with the surgical robotsystem. As an example, the tracking devices may be one or more cameras200, 326 associated with the surgical robot system 100, 300 and may alsotrack tracking array 612 for a defined domain or relative orientationsof the instrument 608 in relation to the robot arm 604, the robot base610, end-effector 602, and/or the patient 210. The tracking devices maybe consistent with those structures described in connection with camerastand 302 and tracking subsystem 532.

FIGS. 7A, 7B, and 7C illustrate a top view, front view, and side view,respectively, of end-effector 602 consistent with an exemplaryembodiment. End-effector 602 may comprise one or more tracking markers702. Tracking markers 702 may be light emitting diodes or other types ofactive and passive markers, such as tracking markers 118 that have beenpreviously described. In an exemplary embodiment, the tracking markers702 are active infrared-emitting markers that are activated by anelectrical signal (e.g., infrared light emitting diodes (LEDs)). Thus,tracking markers 702 may be activated such that the infrared markers 702are visible to the camera 200, 326 or may be deactivated such that theinfrared markers 702 are not visible to the camera 200, 326. Thus, whenthe markers 702 are active, the end-effector 602 may be controlled bythe system 100, 300, 600, and when the markers 702 are deactivated, theend-effector 602 may be locked in position and unable to be moved by thesystem 100, 300, 600.

Markers 702 may be disposed on or within end-effector 602 in a mannersuch that the markers 702 are visible by one or more cameras 200, 326 orother tracking devices associated with the surgical robot system 100,300, 600. The camera 200, 326 or other tracking devices may trackend-effector 602 as it moves to different positions and viewing anglesby following the movement of tracking markers 702. The location ofmarkers 702 and/or end-effector 602 may be shown on a display 110, 304associated with the surgical robot system 100, 300, 600, for example,display 110 as shown in FIG. 2 and/or display 304 shown in FIG. 3. Thisdisplay 110, 304 may allow a user to ensure that end-effector 602 is ina desirable position in relation to robot arm 604, robot base 610, thepatient 210, and/or the user.

For example, as shown in FIG. 7A, markers 702 may be placed around thesurface of end-effector 602 so that a tracking device placed away fromthe surgical field 208 and facing toward the robot 102, 301 and thecamera 200, 326 is able to view at least 3 of the markers 702 through arange of common orientations of the end-effector 602 relative to thetracking device 100, 300, 600. For example, distribution of markers 702in this way allows end-effector 602 to be monitored by the trackingdevices when end-effector 602 is translated and rotated in the surgicalfield 208.

In addition, in exemplary embodiments, end-effector 602 may be equippedwith infrared (IR) receivers that can detect when an external camera200, 326 is getting ready to read markers 702. Upon this detection,end-effector 602 may then illuminate markers 702. The detection by theIR receivers that the external camera 200, 326 is ready to read markers702 may signal the need to synchronize a duty cycle of markers 702,which may be light emitting diodes, to an external camera 200, 326. Thismay also allow for lower power consumption by the robotic system as awhole, whereby markers 702 would only be illuminated at the appropriatetime instead of being illuminated continuously. Further, in exemplaryembodiments, markers 702 may be powered off to prevent interference withother navigation tools, such as different types of surgical instruments608.

FIG. 8 depicts one type of surgical instrument 608 including a trackingarray 612 and tracking markers 804. Tracking markers 804 may be of anytype described herein including but not limited to light emitting diodesor reflective spheres. Markers 804 are monitored by tracking devicesassociated with the surgical robot system 100, 300, 600 and may be oneor more of the line of sight cameras 200, 326. The cameras 200, 326 maytrack the location of instrument 608 based on the position andorientation of tracking array 612 and markers 804. A user, such as asurgeon 120, may orient instrument 608 in a manner so that trackingarray 612 and markers 804 are sufficiently recognized by the trackingdevice or camera 200, 326 to display instrument 608 and markers 804 on,for example, display 110 of the exemplary surgical robot system.

The manner in which a surgeon 120 may place instrument 608 into guidetube 606 of the end-effector 602 and adjust the instrument 608 isevident in FIG. 8. The hollow tube or guide tube 114, 606 of theend-effector 112, 310, 602 is sized and configured to receive at least aportion of the surgical instrument 608. The guide tube 114, 606 isconfigured to be oriented by the robot arm 104 such that insertion andtrajectory for the surgical instrument 608 is able to reach a desiredanatomical target within or upon the body of the patient 210. Thesurgical instrument 608 may include at least a portion of a generallycylindrical instrument. Although a screw driver is exemplified as thesurgical tool 608, it will be appreciated that any suitable surgicaltool 608 may be positioned by the end-effector 602. By way of example,the surgical instrument 608 may include one or more of a guide wire,cannula, a retractor, a drill, a reamer, a screw driver, an insertiontool, a removal tool, or the like. Although the hollow tube 114, 606 isgenerally shown as having a cylindrical configuration, it will beappreciated by those of skill in the art that the guide tube 114, 606may have any suitable shape, size and configuration desired toaccommodate the surgical instrument 608 and access the surgical site.

FIGS. 9A-9C illustrate end-effector 602 and a portion of robot arm 604consistent with an exemplary embodiment. End-effector 602 may furthercomprise body 1202 and clamp 1204. Clamp 1204 may comprise handle 1206,balls 1208, spring 1210, and lip 1212. Robot arm 604 may furthercomprise depressions 1214, mounting plate 1216, lip 1218, and magnets1220.

End-effector 602 may mechanically interface and/or engage with thesurgical robot system and robot arm 604 through one or more couplings.For example, end-effector 602 may engage with robot arm 604 through alocating coupling and/or a reinforcing coupling. Through thesecouplings, end-effector 602 may fasten with robot arm 604 outside aflexible and sterile barrier. In an exemplary embodiment, the locatingcoupling may be a magnetically kinematic mount and the reinforcingcoupling may be a five bar over center clamping linkage.

With respect to the locating coupling, robot arm 604 may comprisemounting plate 1216, which may be non-magnetic material, one or moredepressions 1214, lip 1218, and magnets 1220. Magnet 1220 is mountedbelow each of depressions 1214. Portions of clamp 1204 may comprisemagnetic material and be attracted by one or more magnets 1220. Throughthe magnetic attraction of clamp 1204 and robot arm 604, balls 1208become seated into respective depressions 1214. For example, balls 1208as shown in FIG. 9B would be seated in depressions 1214 as shown in FIG.9A. This seating may be considered a magnetically-assisted kinematiccoupling. Magnets 1220 may be configured to be strong enough to supportthe entire weight of end-effector 602 regardless of the orientation ofend-effector 602. The locating coupling may be any style of kinematicmount that uniquely restrains six degrees of freedom.

With respect to the reinforcing coupling, portions of clamp 1204 may beconfigured to be a fixed ground link and as such clamp 1204 may serve asa five bar linkage. Closing clamp handle 1206 may fasten end-effector602 to robot arm 604 as lip 1212 and lip 1218 engage clamp 1204 in amanner to secure end-effector 602 and robot arm 604. When clamp handle1206 is closed, spring 1210 may be stretched or stressed while clamp1204 is in a locked position. The locked position may be a position thatprovides for linkage past center. Because of a closed position that ispast center, the linkage will not open absent a force applied to clamphandle 1206 to release clamp 1204. Thus, in a locked positionend-effector 602 may be robustly secured to robot arm 604.

Spring 1210 may be a curved beam in tension. Spring 1210 may becomprised of a material that exhibits high stiffness and high yieldstrain such as virgin PEEK (poly-ether-ether-ketone). The linkagebetween end-effector 602 and robot arm 604 may provide for a sterilebarrier between end-effector 602 and robot arm 604 without impedingfastening of the two couplings.

The reinforcing coupling may be a linkage with multiple spring members.The reinforcing coupling may latch with a cam or friction basedmechanism. The reinforcing coupling may also be a sufficiently powerfulelectromagnet that will support fastening end-effector 102 to robot arm604. The reinforcing coupling may be a multi-piece collar completelyseparate from either end-effector 602 and/or robot arm 604 that slipsover an interface between end-effector 602 and robot arm 604 andtightens with a screw mechanism, an over center linkage, or a cammechanism.

Referring to FIGS. 10 and 11, prior to or during a surgical procedure,certain registration procedures may be conducted in order to trackobjects and a target anatomical structure of the patient 210 both in anavigation space and an image space. In order to conduct suchregistration, a registration system 1400 may be used as illustrated inFIG. 10.

In order to track the position of the patient 210, a patient trackingdevice 116 may include a patient fixation instrument 1402 to be securedto a rigid anatomical structure of the patient 210 and a dynamicreference base (DRB) 1404 may be securely attached to the patientfixation instrument 1402. For example, patient fixation instrument 1402may be inserted into opening 1406 of dynamic reference base 1404.Dynamic reference base 1404 may contain markers 1408 that are visible totracking devices, such as tracking subsystem 532. These markers 1408 maybe optical markers or reflective spheres, such as tracking markers 118,as previously discussed herein.

Patient fixation instrument 1402 is attached to a rigid anatomy of thepatient 210 and may remain attached throughout the surgical procedure.In an exemplary embodiment, patient fixation instrument 1402 is attachedto a rigid area of the patient 210, for example, a bone that is locatedaway from the targeted anatomical structure subject to the surgicalprocedure. In order to track the targeted anatomical structure, dynamicreference base 1404 is associated with the targeted anatomical structurethrough the use of a registration fixture that is temporarily placed onor near the targeted anatomical structure in order to register thedynamic reference base 1404 with the location of the targeted anatomicalstructure.

A registration fixture 1410 is attached to patient fixation instrument1402 through the use of a pivot arm 1412. Pivot arm 1412 is attached topatient fixation instrument 1402 by inserting patient fixationinstrument 1402 through an opening 1414 of registration fixture 1410.Pivot arm 1412 is attached to registration fixture 1410 by, for example,inserting a knob 1416 through an opening 1418 of pivot arm 1412.

Using pivot arm 1412, registration fixture 1410 may be placed over thetargeted anatomical structure and its location may be determined in animage space and navigation space using tracking markers 1420 and/orfiducials 1422 on registration fixture 1410. Registration fixture 1410may contain a collection of markers 1420 that are visible in anavigational space (for example, markers 1420 may be detectable bytracking subsystem 532). Tracking markers 1420 may be optical markersvisible in infrared light as previously described herein. Registrationfixture 1410 may also contain a collection of fiducials 1422, forexample, such as bearing balls, that are visible in an imaging space(for example, a three dimension CT image). As described in greaterdetail with respect to FIG. 11, using registration fixture 1410, thetargeted anatomical structure may be associated with dynamic referencebase 1404 thereby allowing depictions of objects in the navigationalspace to be overlaid on images of the anatomical structure. Dynamicreference base 1404, located at a position away from the targetedanatomical structure, may become a reference point thereby allowingremoval of registration fixture 1410 and/or pivot arm 1412 from thesurgical area.

FIG. 11 provides an exemplary method 1500 for registration consistentwith the present disclosure. Method 1500 begins at step 1502 wherein agraphical representation (or image(s)) of the targeted anatomicalstructure may be imported into system 100, 300 600, for example computer408. The graphical representation may be three dimensional CT or afluoroscope scan of the targeted anatomical structure of the patient 210which includes registration fixture 1410 and a detectable imagingpattern of fiducials 1420.

At step 1504, an imaging pattern of fiducials 1420 is detected andregistered in the imaging space and stored in computer 408. Optionally,at this time at step 1506, a graphical representation of theregistration fixture 1410 may be overlaid on the images of the targetedanatomical structure.

At step 1508, a navigational pattern of registration fixture 1410 isdetected and registered by recognizing markers 1420. Markers 1420 may beoptical markers that are recognized in the navigation space throughinfrared light by tracking subsystem 532 via position sensor 540. Thus,the location, orientation, and other information of the targetedanatomical structure is registered in the navigation space. Therefore,registration fixture 1410 may be recognized in both the image spacethrough the use of fiducials 1422 and the navigation space through theuse of markers 1420. At step 1510, the registration of registrationfixture 1410 in the image space is transferred to the navigation space.This transferal is done, for example, by using the relative position ofthe imaging pattern of fiducials 1422 compared to the position of thenavigation pattern of markers 1420.

At step 1512, registration of the navigation space of registrationfixture 1410 (having been registered with the image space) is furthertransferred to the navigation space of dynamic registration array 1404attached to patient fixture instrument 1402. Thus, registration fixture1410 may be removed and dynamic reference base 1404 may be used to trackthe targeted anatomical structure in both the navigation and image spacebecause the navigation space is associated with the image space.

At steps 1514 and 1516, the navigation space may be overlaid on theimage space and objects with markers visible in the navigation space(for example, surgical instruments 608 with optical markers 804). Theobjects may be tracked through graphical representations of the surgicalinstrument 608 on the images of the targeted anatomical structure.

FIGS. 12A-12B illustrate imaging devices 1304 that may be used inconjunction with robot systems 100, 300, 600 to acquire pre-operative,intra-operative, post-operative, and/or real-time image data of patient210. Any appropriate subject matter may be imaged for any appropriateprocedure using the imaging system 1304. The imaging system 1304 may beany imaging device such as imaging device 1306 and/or a C-arm 1308device. It may be desirable to take x-rays of patient 210 from a numberof different positions, without the need for frequent manualrepositioning of patient 210 which may be required in an x-ray system.As illustrated in FIG. 12A, the imaging system 1304 may be in the formof a C-arm 1308 that includes an elongated C-shaped member terminatingin opposing distal ends 1312 of the “C” shape. C-shaped member 1130 mayfurther comprise an x-ray source 1314 and an image receptor 1316. Thespace within C-arm 1308 of the arm may provide room for the physician toattend to the patient substantially free of interference from x-raysupport structure 1318. As illustrated in FIG. 12B, the imaging systemmay include imaging device 1306 having a gantry housing 1324 attached toa support structure imaging device support structure 1328, such as awheeled mobile cart 1330 with wheels 1332, which may enclose an imagecapturing portion, not illustrated. The image capturing portion mayinclude an x-ray source and/or emission portion and an x-ray receivingand/or image receiving portion, which may be disposed about one hundredand eighty degrees from each other and mounted on a rotor (notillustrated) relative to a track of the image capturing portion. Theimage capturing portion may be operable to rotate three hundred andsixty degrees during image acquisition. The image capturing portion mayrotate around a central point and/or axis, allowing image data ofpatient 210 to be acquired from multiple directions or in multipleplanes. Although certain imaging systems 1304 are exemplified herein, itwill be appreciated that any suitable imaging system may be selected byone of ordinary skill in the art.

Turning now to FIGS. 13A-13C, the surgical robot system 100, 300, 600relies on accurate positioning of the end-effector 112, 602, surgicalinstruments 608, and/or the patient 210 (e.g., patient tracking device116) relative to the desired surgical area. In the embodiments shown inFIGS. 13A-13C, the tracking markers 118, 804 are rigidly attached to aportion of the instrument 608 and/or end-effector 112.

FIG. 13A depicts part of the surgical robot system 100 with the robot102 including base 106, robot arm 104, and end-effector 112. The otherelements, not illustrated, such as the display, cameras, etc. may alsobe present as described herein. FIG. 13B depicts a close-up view of theend-effector 112 with guide tube 114 and a plurality of tracking markers118 rigidly affixed to the end-effector 112. In this embodiment, theplurality of tracking markers 118 are attached to the guide tube 112.FIG. 13C depicts an instrument 608 (in this case, a probe 608A) with aplurality of tracking markers 804 rigidly affixed to the instrument 608.As described elsewhere herein, the instrument 608 could include anysuitable surgical instrument, such as, but not limited to, guide wire,cannula, a retractor, a drill, a reamer, a screw driver, an insertiontool, a removal tool, or the like.

When tracking an instrument 608, end-effector 112, or other object to betracked in 3D, an array of tracking markers 118, 804 may be rigidlyattached to a portion of the tool 608 or end-effector 112. Preferably,the tracking markers 118, 804 are attached such that the markers 118,804 are out of the way (e.g., not impeding the surgical operation,visibility, etc.). The markers 118, 804 may be affixed to the instrument608, end-effector 112, or other object to be tracked, for example, withan array 612. Usually three or four markers 118, 804 are used with anarray 612. The array 612 may include a linear section, a cross piece,and may be asymmetric such that the markers 118, 804 are at differentrelative positions and locations with respect to one another. Forexample, as shown in FIG. 13C, a probe 608A with a 4-marker trackingarray 612 is shown, and FIG. 13B depicts the end-effector 112 with adifferent 4-marker tracking array 612.

In FIG. 13C, the tracking array 612 functions as the handle 620 of theprobe 608A. Thus, the four markers 804 are attached to the handle 620 ofthe probe 608A, which is out of the way of the shaft 622 and tip 624.Stereophotogrammetric tracking of these four markers 804 allows theinstrument 608 to be tracked as a rigid body and for the tracking system100, 300, 600 to precisely determine the position of the tip 624 and theorientation of the shaft 622 while the probe 608A is moved around infront of tracking cameras 200, 326.

To enable automatic tracking of one or more tools 608, end-effector 112,or other object to be tracked in 3D (e.g., multiple rigid bodies), themarkers 118, 804 on each tool 608, end-effector 112, or the like, arearranged asymmetrically with a known inter-marker spacing. The reasonfor asymmetric alignment is so that it is unambiguous which marker 118,804 corresponds to a particular location on the rigid body and whethermarkers 118, 804 are being viewed from the front or back, i.e.,mirrored. For example, if the markers 118, 804 were arranged in a squareon the tool 608 or end-effector 112, it would be unclear to the system100, 300, 600 which marker 118, 804 corresponded to which corner of thesquare. For example, for the probe 608A, it would be unclear whichmarker 804 was closest to the shaft 622. Thus, it would be unknown whichway the shaft 622 was extending from the array 612. Accordingly, eacharray 612 and thus each tool 608, end-effector 112, or other object tobe tracked should have a unique marker pattern to allow it to bedistinguished from other tools 608 or other objects being tracked.Asymmetry and unique marker patterns allow the system 100, 300, 600 todetect individual markers 118, 804 then to check the marker spacingagainst a stored template to determine which tool 608, end effector 112,or other object they represent. Detected markers 118, 804 can then besorted automatically and assigned to each tracked object in the correctorder. Without this information, rigid body calculations could not thenbe performed to extract key geometric information, for example, such astool tip 624 and alignment of the shaft 622, unless the user manuallyspecified which detected marker 118, 804 corresponded to which positionon each rigid body. These concepts are commonly known to those skilledin the methods of 3D optical tracking.

Turning now to FIGS. 14A-14D, an alternative version of an end-effector912 with moveable tracking markers 918A-918D is shown. In FIG. 14A, anarray with moveable tracking markers 918A-918D are shown in a firstconfiguration, and in FIG. 14B the moveable tracking markers 918A-918Dare shown in a second configuration, which is angled relative to thefirst configuration. FIG. 14C shows the template of the tracking markers918A-918D, for example, as seen by the cameras 200, 326 in the firstconfiguration of FIG. 14A; and FIG. 14D shows the template of trackingmarkers 918A-918D, for example, as seen by the cameras 200, 326 in thesecond configuration of FIG. 14B.

In this embodiment, 4-marker array tracking is contemplated wherein themarkers 918A-918D are not all in fixed position relative to the rigidbody and instead, one or more of the array markers 918A-918D can beadjusted, for example, during testing, to give updated information aboutthe rigid body that is being tracked without disrupting the process forautomatic detection and sorting of the tracked markers 918A-918D.

When tracking any tool, such as a guide tube 914 connected to the endeffector 912 of a robot system 100, 300, 600, the tracking array'sprimary purpose is to update the position of the end effector 912 in thecamera coordinate system. When using the rigid system, for example, asshown in FIG. 13B, the array 612 of reflective markers 118 rigidlyextend from the guide tube 114. Because the tracking markers 118 arerigidly connected, knowledge of the marker locations in the cameracoordinate system also provides exact location of the centerline, tip,and tail of the guide tube 114 in the camera coordinate system.Typically, information about the position of the end effector 112 fromsuch an array 612 and information about the location of a targettrajectory from another tracked source are used to calculate therequired moves that must be input for each axis of the robot 102 thatwill move the guide tube 114 into alignment with the trajectory and movethe tip to a particular location along the trajectory vector.

Sometimes, the desired trajectory is in an awkward or unreachablelocation, but if the guide tube 114 could be swiveled, it could bereached. For example, a very steep trajectory pointing away from thebase 106 of the robot 102 might be reachable if the guide tube 114 couldbe swiveled upward beyond the limit of the pitch (wrist up-down angle)axis, but might not be reachable if the guide tube 114 is attachedparallel to the plate connecting it to the end of the wrist. To reachsuch a trajectory, the base 106 of the robot 102 might be moved or adifferent end effector 112 with a different guide tube attachment mightbe exchanged with the working end effector. Both of these solutions maybe time consuming and cumbersome.

As best seen in FIGS. 14A and 14B, if the array 908 is configured suchthat one or more of the markers 918A-918D are not in a fixed positionand instead, one or more of the markers 918A-918D can be adjusted,swiveled, pivoted, or moved, the robot 102 can provide updatedinformation about the object being tracked without disrupting thedetection and tracking process. For example, one of the markers918A-918D may be fixed in position and the other markers 918A-918D maybe moveable; two of the markers 918A-918D may be fixed in position andthe other markers 918A-918D may be moveable; three of the markers918A-918D may be fixed in position and the other marker 918A-918D may bemoveable; or all of the markers 918A-918D may be moveable.

In the embodiment shown in FIGS. 14A and 14B, markers 918A, 918 B arerigidly connected directly to a base 906 of the end-effector 912, andmarkers 918C, 918D are rigidly connected to the tube 914. Similar toarray 612, array 908 may be provided to attach the markers 918A-918D tothe end-effector 912, instrument 608, or other object to be tracked. Inthis case, however, the array 908 is comprised of a plurality ofseparate components. For example, markers 918A, 918B may be connected tothe base 906 with a first array 908A, and markers 918C, 918D may beconnected to the guide tube 914 with a second array 908B. Marker 918Amay be affixed to a first end of the first array 908A and marker 918Bmay be separated a linear distance and affixed to a second end of thefirst array 908A. While first array 908 is substantially linear, secondarray 908B has a bent or V-shaped configuration, with respective rootends, connected to the guide tube 914, and diverging therefrom to distalends in a V-shape with marker 918C at one distal end and marker 918D atthe other distal end. Although specific configurations are exemplifiedherein, it will be appreciated that other asymmetric designs includingdifferent numbers and types of arrays 908A, 908B and differentarrangements, numbers, and types of markers 918A-918D are contemplated.

The guide tube 914 may be moveable, swivelable, or pivotable relative tothe base 906, for example, across a hinge 920 or other connector to thebase 906. Thus, markers 918C, 918D are moveable such that when the guidetube 914 pivots, swivels, or moves, markers 918C, 918D also pivot,swivel, or move. As best seen in FIG. 14A, guide tube 914 has alongitudinal axis 916 which is aligned in a substantially normal orvertical orientation such that markers 918A-918D have a firstconfiguration. Turning now to FIG. 14B, the guide tube 914 is pivoted,swiveled, or moved such that the longitudinal axis 916 is now angledrelative to the vertical orientation such that markers 918A-918D have asecond configuration, different from the first configuration.

In contrast to the embodiment described for FIGS. 14A-14D, if a swivelexisted between the guide tube 914 and the arm 104 (e.g., the wristattachment) with all four markers 918A-918D remaining attached rigidlyto the guide tube 914 and this swivel was adjusted by the user, therobotic system 100, 300, 600 would not be able to automatically detectthat the guide tube 914 orientation had changed. The robotic system 100,300, 600 would track the positions of the marker array 908 and wouldcalculate incorrect robot axis moves assuming the guide tube 914 wasattached to the wrist (the robot arm 104) in the previous orientation.By keeping one or more markers 918A-918D (e.g., two markers 918C, 918D)rigidly on the tube 914 and one or more markers 918A-918D (e.g., twomarkers 918A, 918B) across the swivel, automatic detection of the newposition becomes possible and correct robot moves are calculated basedon the detection of a new tool or end-effector 112, 912 on the end ofthe robot arm 104.

One or more of the markers 918A-918D are configured to be moved,pivoted, swiveled, or the like according to any suitable means. Forexample, the markers 918A-918D may be moved by a hinge 920, such as aclamp, spring, lever, slide, toggle, or the like, or any other suitablemechanism for moving the markers 918A-918D individually or incombination, moving the arrays 908A, 908B individually or incombination, moving any portion of the end-effector 912 relative toanother portion, or moving any portion of the tool 608 relative toanother portion.

As shown in FIGS. 14A and 14B, the array 908 and guide tube 914 maybecome reconfigurable by simply loosening the clamp or hinge 920, movingpart of the array 908A, 908B relative to the other part 908A, 908B, andretightening the hinge 920 such that the guide tube 914 is oriented in adifferent position. For example, two markers 918C, 918D may be rigidlyinterconnected with the tube 914 and two markers 918A, 918B may berigidly interconnected across the hinge 920 to the base 906 of theend-effector 912 that attaches to the robot arm 104. The hinge 920 maybe in the form of a clamp, such as a wing nut or the like, which can beloosened and retightened to allow the user to quickly switch between thefirst configuration (FIG. 14A) and the second configuration (FIG. 14B).

The cameras 200, 326 detect the markers 918A-918D, for example, in oneof the templates identified in FIGS. 14C and 14D. If the array 908 is inthe first configuration (FIG. 14A) and tracking cameras 200, 326 detectthe markers 918A-918D, then the tracked markers match Array Template 1as shown in FIG. 14C. If the array 908 is the second configuration (FIG.14B) and tracking cameras 200, 326 detect the same markers 918A-918D,then the tracked markers match Array Template 2 as shown in FIG. 14D.Array Template 1 and Array Template 2 are recognized by the system 100,300, 600 as two distinct tools, each with its own uniquely definedspatial relationship between guide tube 914, markers 918A-918D, androbot attachment. The user could therefore adjust the position of theend-effector 912 between the first and second configurations withoutnotifying the system 100, 300, 600 of the change and the system 100,300, 600 would appropriately adjust the movements of the robot 102 tostay on trajectory.

In this embodiment, there are two assembly positions in which the markerarray matches unique templates that allow the system 100, 300, 600 torecognize the assembly as two different tools or two different endeffectors. In any position of the swivel between or outside of these twopositions (namely, Array Template 1 and Array Template 2 shown in FIGS.14C and 14D, respectively), the markers 918A-918D would not match anytemplate and the system 100, 300, 600 would not detect any array presentdespite individual markers 918A-918D being detected by cameras 200, 326,with the result being the same as if the markers 918A-918D weretemporarily blocked from view of the cameras 200, 326. It will beappreciated that other array templates may exist for otherconfigurations, for example, identifying different instruments 608 orother end-effectors 112, 912, etc.

In the embodiment described, two discrete assembly positions are shownin FIGS. 14A and 14B. It will be appreciated, however, that there couldbe multiple discrete positions on a swivel joint, linear joint,combination of swivel and linear joints, pegboard, or other assemblywhere unique marker templates may be created by adjusting the positionof one or more markers 918A-918D of the array relative to the others,with each discrete position matching a particular template and defininga unique tool 608 or end-effector 112, 912 with different knownattributes. In addition, although exemplified for end effector 912, itwill be appreciated that moveable and fixed markers 918A-918D may beused with any suitable instrument 608 or other object to be tracked.

When using an external 3D tracking system 100, 300, 600 to track a fullrigid body array of three or more markers attached to a robot's endeffector 112 (for example, as depicted in FIGS. 13A and 13B), it ispossible to directly track or to calculate the 3D position of everysection of the robot 102 in the coordinate system of the cameras 200,326. The geometric orientations of joints relative to the tracker areknown by design, and the linear or angular positions of joints are knownfrom encoders for each motor of the robot 102, fully defining the 3Dpositions of all of the moving parts from the end effector 112 to thebase 116. Similarly, if a tracker were mounted on the base 106 of therobot 102 (not shown), it is likewise possible to track or calculate the3D position of every section of the robot 102 from base 106 to endeffector 112 based on known joint geometry and joint positions from eachmotor's encoder.

In some situations, it may be desirable to track the positions of allsegments of the robot 102 from fewer than three markers 118 rigidlyattached to the end effector 112. Specifically, if a tool 608 isintroduced into the guide tube 114, it may be desirable to track fullrigid body motion of the robot 902 with only one additional marker 118being tracked.

Turning now to FIGS. 15A-15E, an alternative version of an end-effector1012 having only a single tracking marker 1018 is shown. End-effector1012 may be similar to the other end-effectors described herein, and mayinclude a guide tube 1014 extending along a longitudinal axis 1016. Asingle tracking marker 1018, similar to the other tracking markersdescribed herein, may be rigidly affixed to the guide tube 1014. Thissingle marker 1018 can serve the purpose of adding missing degrees offreedom to allow full rigid body tracking and/or can serve the purposeof acting as a surveillance marker to ensure that assumptions aboutrobot and camera positioning are valid.

The single tracking marker 1018 may be attached to the robotic endeffector 1012 as a rigid extension to the end effector 1012 thatprotrudes in any convenient direction and does not obstruct thesurgeon's view. The tracking marker 1018 may be affixed to the guidetube 1014 or any other suitable location of on the end-effector 1012.When affixed to the guide tube 1014, the tracking marker 1018 may bepositioned at a location between first and second ends of the guide tube1014. For example, in FIG. 15A, the single tracking marker 1018 is shownas a reflective sphere mounted on the end of a narrow shaft 1017 thatextends forward from the guide tube 1014 and is positionedlongitudinally above a mid-point of the guide tube 1014 and below theentry of the guide tube 1014. This position allows the marker 1018 to begenerally visible by cameras 200, 326 but also would not obstruct visionof the surgeon 120 or collide with other tools or objects in thevicinity of surgery. In addition, the guide tube 1014 with the marker1018 in this position is designed for the marker array on any tool 608introduced into the guide tube 1014 to be visible at the same time asthe single marker 1018 on the guide tube 1014 is visible.

As shown in FIG. 15B, when a snugly fitting tool or instrument 608 isplaced within the guide tube 1014, the instrument 608 becomesmechanically constrained in 4 of 6 degrees of freedom. That is, theinstrument 608 cannot be rotated in any direction except about thelongitudinal axis 1016 of the guide tube 1014 and the instrument 608cannot be translated in any direction except along the longitudinal axis1016 of the guide tube 1014. In other words, the instrument 608 can onlybe translated along and rotated about the centerline of the guide tube1014. If two more parameters are known, such as (1) an angle of rotationabout the longitudinal axis 1016 of the guide tube 1014; and (2) aposition along the guide tube 1014, then the position of the endeffector 1012 in the camera coordinate system becomes fully defined.

Referring now to FIG. 15C, the system 100, 300, 600 should be able toknow when a tool 608 is actually positioned inside of the guide tube1014 and is not instead outside of the guide tube 1014 and justsomewhere in view of the cameras 200, 326. The tool 608 has alongitudinal axis or centerline 616 and an array 612 with a plurality oftracked markers 804. The rigid body calculations may be used todetermine where the centerline 616 of the tool 608 is located in thecamera coordinate system based on the tracked position of the array 612on the tool 608.

The fixed normal (perpendicular) distance DF from the single marker 1018to the centerline or longitudinal axis 1016 of the guide tube 1014 isfixed and is known geometrically, and the position of the single marker1018 can be tracked. Therefore, when a detected distance DD from toolcenterline 616 to single marker 1018 matches the known fixed distance DFfrom the guide tube centerline 1016 to the single marker 1018, it can bedetermined that the tool 608 is either within the guide tube 1014(centerlines 616, 1016 of tool 608 and guide tube 1014 coincident) orhappens to be at some point in the locus of possible positions wherethis distance DD matches the fixed distance DF. For example, in FIG.15C, the normal detected distance DD from tool centerline 616 to thesingle marker 1018 matches the fixed distance DF from guide tubecenterline 1016 to the single marker 1018 in both frames of data(tracked marker coordinates) represented by the transparent tool 608 intwo positions, and thus, additional considerations may be needed todetermine when the tool 608 is located in the guide tube 1014.

Turning now to FIG. 15D, programmed logic can be used to look for framesof tracking data in which the detected distance D_(D) from toolcenterline 616 to single marker 1018 remains fixed at the correct lengthdespite the tool 608 moving in space by more than some minimum distancerelative to the single sphere 1018 to satisfy the condition that thetool 608 is moving within the guide tube 1014. For example, a firstframe F1 may be detected with the tool 608 in a first position and asecond frame F2 may be detected with the tool 608 in a second position(namely, moved linearly with respect to the first position). The markers804 on the tool array 612 may move by more than a given amount (e.g.,more than 5 mm total) from the first frame F1 to the second frame F2.Even with this movement, the detected distance D_(D) from the toolcenterline vector C′ to the single marker 1018 is substantiallyidentical in both the first frame F1 and the second frame F2.

Logistically, the surgeon 120 or user could place the tool 608 withinthe guide tube 1014 and slightly rotate it or slide it down into theguide tube 1014 and the system 100, 300, 600 would be able to detectthat the tool 608 is within the guide tube 1014 from tracking of thefive markers (four markers 804 on tool 608 plus single marker 1018 onguide tube 1014). Knowing that the tool 608 is within the guide tube1014, all 6 degrees of freedom may be calculated that define theposition and orientation of the robotic end effector 1012 in space.Without the single marker 1018, even if it is known with certainty thatthe tool 608 is within the guide tube 1014, it is unknown where theguide tube 1014 is located along the tool's centerline vector C′ and howthe guide tube 1014 is rotated relative to the centerline vector C′.

With emphasis on FIG. 15E, the presence of the single marker 1018 beingtracked as well as the four markers 804 on the tool 608, it is possibleto construct the centerline vector C′ of the guide tube 1014 and tool608 and the normal vector through the single marker 1018 and through thecenterline vector C′. This normal vector has an orientation that is in aknown orientation relative to the forearm of the robot distal to thewrist (in this example, oriented parallel to that segment) andintersects the centerline vector C′ at a specific fixed position. Forconvenience, three mutually orthogonal vectors k′, j′, i′ can beconstructed, as shown in FIG. 15E, defining rigid body position andorientation of the guide tube 1014. One of the three mutually orthogonalvectors k′ is constructed from the centerline vector C′, the secondvector j′ is constructed from the normal vector through the singlemarker 1018, and the third vector i′ is the vector cross product of thefirst and second vectors k′, j′. The robot's joint positions relative tothese vectors k′, j′, i′ are known and fixed when all joints are atzero, and therefore rigid body calculations can be used to determine thelocation of any section of the robot relative to these vectors k′, j′,i′ when the robot is at a home position. During robot movement, if thepositions of the tool markers 804 (while the tool 608 is in the guidetube 1014) and the position of the single marker 1018 are detected fromthe tracking system, and angles/linear positions of each joint are knownfrom encoders, then position and orientation of any section of the robotcan be determined.

In some embodiments, it may be useful to fix the orientation of the tool608 relative to the guide tube 1014. For example, the end effector guidetube 1014 may be oriented in a particular position about its axis 1016to allow machining or implant positioning. Although the orientation ofanything attached to the tool 608 inserted into the guide tube 1014 isknown from the tracked markers 804 on the tool 608, the rotationalorientation of the guide tube 1014 itself in the camera coordinatesystem is unknown without the additional tracking marker 1018 (ormultiple tracking markers in other embodiments) on the guide tube 1014.This marker 1018 provides essentially a “clock position” from −180° to+180° based on the orientation of the marker 1018 relative to thecenterline vector C′. Thus, the single marker 1018 can provideadditional degrees of freedom to allow full rigid body tracking and/orcan act as a surveillance marker to ensure that assumptions about therobot and camera positioning are valid.

FIG. 16 is a block diagram of a method 1100 for navigating and movingthe end-effector 1012 (or any other end-effector described herein) ofthe robot 102 to a desired target trajectory. Another use of the singlemarker 1018 on the robotic end effector 1012 or guide tube 1014 is aspart of the method 1100 enabling the automated safe movement of therobot 102 without a full tracking array attached to the robot 102. Thismethod 1100 functions when the tracking cameras 200, 326 do not moverelative to the robot 102 (i.e., they are in a fixed position), thetracking system's coordinate system and robot's coordinate system areco-registered, and the robot 102 is calibrated such that the positionand orientation of the guide tube 1014 can be accurately determined inthe robot's Cartesian coordinate system based only on the encodedpositions of each robotic axis.

For this method 1100, the coordinate systems of the tracker and therobot must be co-registered, meaning that the coordinate transformationfrom the tracking system's Cartesian coordinate system to the robot'sCartesian coordinate system is needed. For convenience, this coordinatetransformation can be a 4×4 matrix of translations and rotations that iswell known in the field of robotics. This transformation will be termedTcr to refer to “transformation—camera to robot”. Once thistransformation is known, any new frame of tracking data, which isreceived as x,y,z coordinates in vector form for each tracked marker,can be multiplied by the 4×4 matrix and the resulting x,y,z coordinateswill be in the robot's coordinate system. To obtain Tcr, a full trackingarray on the robot is tracked while it is rigidly attached to the robotat a location that is known in the robot's coordinate system, then knownrigid body methods are used to calculate the transformation ofcoordinates. It should be evident that any tool 608 inserted into theguide tube 1014 of the robot 102 can provide the same rigid bodyinformation as a rigidly attached array when the additional marker 1018is also read. That is, the tool 608 need only be inserted to anyposition within the guide tube 1014 and at any rotation within the guidetube 1014, not to a fixed position and orientation. Thus, it is possibleto determine Tcr by inserting any tool 608 with a tracking array 612into the guide tube 1014 and reading the tool's array 612 plus thesingle marker 1018 of the guide tube 1014 while at the same timedetermining from the encoders on each axis the current location of theguide tube 1014 in the robot's coordinate system.

Logic for navigating and moving the robot 102 to a target trajectory isprovided in the method 1100 of FIG. 16. Before entering the loop 1102,it is assumed that the transformation Tcr was previously stored. Thus,before entering loop 1102, in step 1104, after the robot base 106 issecured, greater than or equal to one frame of tracking data of a toolinserted in the guide tube while the robot is static is stored; and instep 1106, the transformation of robot guide tube position from cameracoordinates to robot coordinates Tcr is calculated from this static dataand previous calibration data. Tcr should remain valid as long as thecameras 200, 326 do not move relative to the robot 102. If the cameras200, 326 move relative to the robot 102, and Tcr needs to bere-obtained, the system 100, 300, 600 can be made to prompt the user toinsert a tool 608 into the guide tube 1014 and then automaticallyperform the necessary calculations.

In the flowchart of method 1100, each frame of data collected consistsof the tracked position of the DRB 1404 on the patient 210, the trackedposition of the single marker 1018 on the end effector 1014, and asnapshot of the positions of each robotic axis. From the positions ofthe robot's axes, the location of the single marker 1018 on the endeffector 1012 is calculated. This calculated position is compared to theactual position of the marker 1018 as recorded from the tracking system.If the values agree, it can be assured that the robot 102 is in a knownlocation. The transformation Tcr is applied to the tracked position ofthe DRB 1404 so that the target for the robot 102 can be provided interms of the robot's coordinate system. The robot 102 can then becommanded to move to reach the target.

After steps 1104, 1106, loop 1102 includes step 1108 receiving rigidbody information for DRB 1404 from the tracking system; step 1110transforming target tip and trajectory from image coordinates totracking system coordinates; and step 1112 transforming target tip andtrajectory from camera coordinates to robot coordinates (apply Tcr).Loop 1102 further includes step 1114 receiving a single stray markerposition for robot from tracking system; and step 1116 transforming thesingle stray marker from tracking system coordinates to robotcoordinates (apply stored Tcr). Loop 1102 also includes step 1118determining current location of the single robot marker 1018 in therobot coordinate system from forward kinematics. The information fromsteps 1116 and 1118 is used to determine step 1120 whether the straymarker coordinates from transformed tracked position agree with thecalculated coordinates being less than a given tolerance. If yes,proceed to step 1122, calculate and apply robot move to target x, y, zand trajectory. If no, proceed to step 1124, halt and require full arrayinsertion into guide tube 1014 before proceeding; step 1126 after arrayis inserted, recalculate Tcr; and then proceed to repeat steps 1108,1114, and 1118.

This method 1100 has advantages over a method in which the continuousmonitoring of the single marker 1018 to verify the location is omitted.Without the single marker 1018, it would still be possible to determinethe position of the end effector 1012 using Tcr and to send theend-effector 1012 to a target location but it would not be possible toverify that the robot 102 was actually in the expected location. Forexample, if the cameras 200, 326 had been bumped and Tcr was no longervalid, the robot 102 would move to an erroneous location. For thisreason, the single marker 1018 provides value with regard to safety.

For a given fixed position of the robot 102, it is theoreticallypossible to move the tracking cameras 200, 326 to a new location inwhich the single tracked marker 1018 remains unmoved since it is asingle point, not an array. In such a case, the system 100, 300, 600would not detect any error since there would be agreement in thecalculated and tracked locations of the single marker 1018. However,once the robot's axes caused the guide tube 1012 to move to a newlocation, the calculated and tracked positions would disagree and thesafety check would be effective.

The term “surveillance marker” may be used, for example, in reference toa single marker that is in a fixed location relative to the DRB 1404. Inthis instance, if the DRB 1404 is bumped or otherwise dislodged, therelative location of the surveillance marker changes and the surgeon 120can be alerted that there may be a problem with navigation. Similarly,in the embodiments described herein, with a single marker 1018 on therobot's guide tube 1014, the system 100, 300, 600 can continuously checkwhether the cameras 200, 326 have moved relative to the robot 102. Ifregistration of the tracking system's coordinate system to the robot'scoordinate system is lost, such as by cameras 200, 326 being bumped ormalfunctioning or by the robot malfunctioning, the system 100, 300, 600can alert the user and corrections can be made. Thus, this single marker1018 can also be thought of as a surveillance marker for the robot 102.

It should be clear that with a full array permanently mounted on therobot 102 (e.g., the plurality of tracking markers 702 on end-effector602 shown in FIGS. 7A-7C) such functionality of a single marker 1018 asa robot surveillance marker is not needed because it is not requiredthat the cameras 200, 326 be in a fixed position relative to the robot102, and Tcr is updated at each frame based on the tracked position ofthe robot 102. Reasons to use a single marker 1018 instead of a fullarray are that the full array is more bulky and obtrusive, therebyblocking the surgeon's view and access to the surgical field 208 morethan a single marker 1018, and line of sight to a full array is moreeasily blocked than line of sight to a single marker 1018.

Turning now to FIGS. 17A-17B and 18A-18B, instruments 608, such asimplant holders 608B, 608C, are depicted which include both fixed andmoveable tracking markers 804, 806. The implant holders 608B, 608C mayhave a handle 620 and an outer shaft 622 extending from the handle 620.The shaft 622 may be positioned substantially perpendicular to thehandle 620, as shown, or in any other suitable orientation. An innershaft 626 may extend through the outer shaft 622 with a knob 628 at oneend. Implant 10, 12 connects to the shaft 622, at the other end, at tip624 of the implant holder 608B, 608C using typical connection mechanismsknown to those of skill in the art. The knob 628 may be rotated, forexample, to expand or articulate the implant 10, 12. U.S. Pat. Nos.8,709,086 and 8,491,659, which are incorporated by reference herein,describe expandable fusion devices and methods of installation.

When tracking the tool 608, such as implant holder 608B, 608C, thetracking array 612 may contain a combination of fixed markers 804 andone or more moveable markers 806 which make up the array 612 or isotherwise attached to the implant holder 608B, 608C. The navigationarray 612 may include at least one or more (e.g., at least two) fixedposition markers 804, which are positioned with a known locationrelative to the implant holder instrument 608B, 608C. These fixedmarkers 804 would not be able to move in any orientation relative to theinstrument geometry and would be useful in defining where the instrument608 is in space. In addition, at least one marker 806 is present whichcan be attached to the array 612 or the instrument itself which iscapable of moving within a pre-determined boundary (e.g., sliding,rotating, etc.) relative to the fixed markers 804. The system 100, 300,600 (e.g., the software) correlates the position of the moveable marker806 to a particular position, orientation, or other attribute of theimplant 10 (such as height of an expandable interbody spacer shown inFIGS. 17A-17B or angle of an articulating interbody spacer shown inFIGS. 18A-18B). Thus, the system and/or the user can determine theheight or angle of the implant 10, 12 based on the location of themoveable marker 806.

In the embodiment shown in FIGS. 17A-17B, four fixed markers 804 areused to define the implant holder 608B and a fifth moveable marker 806is able to slide within a pre-determined path to provide feedback on theimplant height (e.g., a contracted position or an expanded position).FIG. 17A shows the expandable spacer 10 at its initial height, and FIG.17B shows the spacer 10 in the expanded state with the moveable marker806 translated to a different position. In this case, the moveablemarker 806 moves closer to the fixed markers 804 when the implant 10 isexpanded, although it is contemplated that this movement may be reversedor otherwise different. The amount of linear translation of the marker806 would correspond to the height of the implant 10. Although only twopositions are shown, it would be possible to have this as a continuousfunction whereby any given expansion height could be correlated to aspecific position of the moveable marker 806.

Turning now to FIGS. 18A-18B, four fixed markers 804 are used to definethe implant holder 608C and a fifth, moveable marker 806 is configuredto slide within a pre-determined path to provide feedback on the implantarticulation angle. FIG. 18A shows the articulating spacer 12 at itsinitial linear state, and FIG. 18B shows the spacer 12 in an articulatedstate at some offset angle with the moveable marker 806 translated to adifferent position. The amount of linear translation of the marker 806would correspond to the articulation angle of the implant 12. Althoughonly two positions are shown, it would be possible to have this as acontinuous function whereby any given articulation angle could becorrelated to a specific position of the moveable marker 806.

In these embodiments, the moveable marker 806 slides continuously toprovide feedback about an attribute of the implant 10, 12 based onposition. It is also contemplated that there may be discreet positionsthat the moveable marker 806 must be in which would also be able toprovide further information about an implant attribute. In this case,each discreet configuration of all markers 804, 806 correlates to aspecific geometry of the implant holder 608B, 608C and the implant 10,12 in a specific orientation or at a specific height. In addition, anymotion of the moveable marker 806 could be used for other variableattributes of any other type of navigated implant.

Although depicted and described with respect to linear movement of themoveable marker 806, the moveable marker 806 should not be limited tojust sliding as there may be applications where rotation of the marker806 or other movements could be useful to provide information about theimplant 10, 12. Any relative change in position between the set of fixedmarkers 804 and the moveable marker 806 could be relevant informationfor the implant 10, 12 or other device. In addition, although expandableand articulating implants 10, 12 are exemplified, the instrument 608could work with other medical devices and materials, such as spacers,cages, plates, fasteners, nails, screws, rods, pins, wire structures,sutures, anchor clips, staples, stents, bone grafts, biologics, cements,or the like.

Turning now to FIG. 19A, it is envisioned that the robot end-effector112 is interchangeable with other types of end-effectors 112. Moreover,it is contemplated that each end-effector 112 may be able to perform oneor more functions based on a desired surgical procedure. For example,the end-effector 112 having a guide tube 114 may be used for guiding aninstrument 608 as described herein. In addition, end-effector 112 may bereplaced with a different or alternative end-effector 112 that controlsa surgical device, instrument, or implant, for example.

The alternative end-effector 112 may include one or more devices orinstruments coupled to and controllable by the robot. By way ofnon-limiting example, the end-effector 112, as depicted in FIG. 19A, maycomprise a retractor (for example, one or more retractors disclosed inU.S. Pat. Nos. 8,992,425 and 8,968,363) or one or more mechanisms forinserting or installing surgical devices such as expandableintervertebral fusion devices (such as expandable implants exemplifiedin U.S. Pat. Nos. 8,845,734; 9,510,954; and 9,456,903), stand-aloneintervertebral fusion devices (such as implants exemplified in U.S. Pat.Nos. 9,364,343 and 9,480,579), expandable corpectomy devices (such ascorpectomy implants exemplified in U.S. Pat. Nos. 9,393,128 and9,173,747), articulating spacers (such as implants exemplified in U.S.Pat. No. 9,259,327), facet prostheses (such as devices exemplified inU.S. Pat. No. 9,539,031), laminoplasty devices (such as devicesexemplified in U.S. Pat. No. 9,486,253), spinous process spacers (suchas implants exemplified in U.S. Pat. No. 9,592,082), inflatables,fasteners including polyaxial screws, uniplanar screws, pedicle screws,posted screws, and the like, bone fixation plates, rod constructs andrevision devices (such as devices exemplified in U.S. Pat. No.8,882,803), artificial and natural discs, motion preserving devices andimplants, spinal cord stimulators (such as devices exemplified in U.S.Pat. No. 9,440,076), and other surgical devices. The end-effector 112may include one or instruments directly or indirectly coupled to therobot for providing bone cement, bone grafts, living cells,pharmaceuticals, or other deliverable to a surgical target. Theend-effector 112 may also include one or more instruments designed forperforming a discectomy, kyphoplasty, vertebrostenting, dilation, orother surgical procedure.

The end-effector itself and/or the implant, device, or instrument mayinclude one or more markers 118 such that the location and position ofthe markers 118 may be identified in three-dimensions. It iscontemplated that the markers 118 may include active or passive markers118, as described herein, that may be directly or indirectly visible tothe cameras 200. Thus, one or more markers 118 located on an implant 10,for example, may provide for tracking of the implant 10 before, during,and after implantation.

As shown in FIG. 19B, the end-effector 112 may include an instrument 608or portion thereof that is coupled to the robot arm 104 (for example,the instrument 608 may be coupled to the robot arm 104 by the couplingmechanism shown in FIGS. 9A-9C) and is controllable by the robot system100. Thus, in the embodiment shown in FIG. 19B, the robot system 100 isable to insert implant 10 into a patient and expand or contract theexpandable implant 10. Accordingly, the robot system 100 may beconfigured to assist a surgeon or to operate partially or completelyindependently thereof. Thus, it is envisioned that the robot system 100may be capable of controlling each alternative end-effector 112 for itsspecified function or surgical procedure.

Turning now to FIGS. 20 and 21, FIG. 20 depicts a guide tube 2000 andFIG. 21 depicts a surgical tool 2002 consistent with the principles ofthe present disclosure. Guide tube 2000 may include internal threading2004 and surgical tool 2002 may include external threading 2006 thatmatches internal threading 2004.

One reason for providing a threaded attachment between guide tube 2000and surgical tool 2002 is to aid in driving an implant (such as a screw)into bone to prevent stripping and/or improper purchase. Substantialdriving power to screws and other tools such as awls, drills, needles orprobes is provided by means of matching internal threads on anend-effector (via guide tube 2000 and threads 2004) and external threads2006 on the surgical tool. Using the interlocking power of the threads2004 and 2006 may allow the end-effector to assist in driving the toolsinto hard tissues such as bone during operation.

In addition to providing an increased ability to exert longitudinalforce, the threading also provides a more uniform forward thrust than ispossible during freehand screw insertion. For example, when a surgeondrives a pointed awl through bone, the awl is likely to jump suddenlyforward when it exits the bone due to the decreased tissue resistanceand the inability of the surgeon to react rapidly to decrease the amountof force that they are exerting. With the threaded interface, the rateof advancement is controlled. Although there may be a sudden recoil oftissue when applied force changes, the tool's forward advancementremains at a fixed rate. By providing force feedback to the robotic arm,this tissue recoil can also be countered by automatic servo control ofthe robot instructing it to back up in such a circumstance. For example,when applying a forward thrust through bone on an awl, the tissueresistance might be high and the bone might be flexing elasticallybackward in the direction of thrust. Once the awl penetrates all the waythrough the bone, the elastic tension might cause the piece of bone tomove forward against the direction of thrust, sliding suddenly up theawl like a skewer. If the robot is continuously monitoring appliedforce, it can use the force feedback to respond when a sudden drop inresistance beyond some triggering threshold such as 10% is felt,assuming that the 10% drop means penetration has occurred. At the pointof penetration, the robot could then switch to a mode that would use theapplied force feedback to control the position of the end effector alongthe trajectory (thrust) vector, moving backward under feedback controlto a point of zero forward or reverse force and preventing soft tissuedamage.

Robotically controlled guide tube 2000 is threaded on its interior wall(threads 2004 shown as dotted lines in FIG. 20). Threads 2004 mate withmatching threads 2006 on the exterior surface of the surgical tool 2002.By incorporating threads 2004 into guide tube 2000 and threads 2006 intoa tool such as a screwdriver and then matching the pitch of threads 2004and 2006 to that of a screw attached to the end of the screwdriver andbeing inserted into a patient, the screw would be forced to advance whensurgical tool 2002 is rotated. If threads 2004 and 2006 have a finer orcoarser pitch than the threads of the screw being inserted, the screwmay strip (shear) in the bone as it advances. To ensure that the screwadvances at the correct rate, the pitch of threads 2004 and 2006 can beselected to match the pitch of the screw itself. Differentinterchangeable guide tubes and mating tools could be provided to theuser, who could manually select the guide tube and tool to match thepitch of the screw being used. Alternatively, an auto tool changer couldautomatically select the appropriate threading to match the screwselected through software and automatically load the tool on to the endeffector of the robot. Also, an insert that slides into the guide tubecould be inserted automatically or manually that would have correctthreading. Similarly, an external sleeve shaped as a cylindricalthreaded shell could be automatically or manually attached to theoutside of a tool with correct threading for the screw being inserted.

In the scenario discussed above, tool 2002 when used with thread pitchmatching the pitch of the screw being inserted is less likely to stripthe screw by rotating it without advancing, which may occur with afreehand screw insertion when a tool in a guide tube is allowed tofreely move along a longitudinal axis of a guide tube. Additionally, dueto the use of the robotic system, the user may leverage the rigidity ofthe threads and the force of the robotic arm to help drive the screw ortool downward and into the bone more forcefully and evenly.

Corresponding the pitches of the threads of guide tube, tool, and thescrew may ensure that the screw receives an enhanced ability to driveinto the bone. This force enhancement may be further assisted by theforce of the robotic arm itself. By using the robotic arm's power tohelp force the tool downward along the trajectory path into the bone,the effectiveness of the hole preparation and screw insertion increasesand the surgeon's concern about the possibility of stripping the screwand wasting materials or harming the patient reduces.

In addition, guide tube 2000 may be provided with a mechanism that mayselectively allow or prevent rotational movement of the tool and screwduring operation. A rotational bearing placed in series at a distal endof the threaded portion of the tool, proximal to the tip of the tool,may restrict the motion of the tool tip to a purely non-rotationaladvancement or withdrawal along the linear path while the proximalportion of the tool is being rotated. Such a rotational bearing may bedisposed for tools that should not rotationally move such as a dilator,needle, awl, or corded drill, which should not spin while it is beingadvanced.

Turning now to FIGS. 22-28C, a robotically controlled dilator system2200 and various components thereof are illustrated and will bedescribed.

FIG. 22 depicts dilator system 2200 in a partially extended state.Dilator system 2200 may include a mount 2202, a center pin 2204, aninner dilator 2206, an outer dilator 2208, and outer sleeve 2210,handles 2212, a threaded cap 2214, a corkscrew rod 2228, a corkscrew rodgrip 2216 and a center shaft 2218. One reason for dilator system 2200may be to provide separate, fine, and uniform control of two or morecomponents of a surgical tool, such as a dilator, by using concentricmount points that can attach to the same drill. With independent controlof multiple components of the tool, a surgeon can force down or retractone portion of the tool without affecting the position of a secondportion of the tool, and vice versa.

In FIG. 22, controlled dilator system 2200 may allow the surgeon toadvance dilator sleeves and a central shaft independently on an endeffector. For example, mount 2202 may be attached to a robotic arm inorder to securely anchor dilator system 2200 in position and at atrajectory in relation to a patient. Center pin 2204 may be advancedinto bone by rotating central shaft 2218, which may be threaded andadvance through system 2200 as described in greater detail below. Innerdilator may be advanced over center pin 2204 by rotating corkscrew rod2228 via corkscrew rod grip 2216. Outer dilator 2208 may be advancedover inner dilator 2206 by pushing down on handles 2212. In an exemplarymethod of operation, a surgeon may attach a cannulated drill either overthe central shaft 2218 near the proximal end of central shaft 2218 or onthe corkscrew rod grip 2216, with the central shaft passing through thecannulated drill, to advance center pin 2204 or inner dilator 2206,respectively. Outer dilator 2208 may be manually advanced by the surgeonby pushing down on handles 2212. Pulling back up on handles 2212 mayretract outer dilator 2208 or keep outer dilator 2208 extended, asdescribed in greater detail below.

Controlled dilator system 2200 may help to circumvent the issue of asurgeon being unable to control mechanisms of a tool independently, suchas lowering one mechanism without altering the position of another.Lowering each mechanism independently if needed and through a threadeddrive mechanism gives the surgeon finer and more uniform control duringsurgery, and using concentric mounting points activated via a shareddrill may allow for a simplified system of engagement.

Referring to FIG. 23, threaded cap 2214 is illustrated in greaterdetail. Threaded cap 2214 may be an anchor point allowing forindependent control of inner dilator 2206 (via corkscrew rod 2228) andcenter pin 2204 (via center shaft 2218). Threaded cap 2214 may include acorkscrew through-hole 2220, threaded through-hole 2222, and threads2224. Threads 2224 are present to allow the threaded cap 2214 to easilyattach to a proximal end of dilator system 2200. The proximal end ofouter tube 2210 is threaded with corresponding threads to receive thethreads 2224 on the threaded cap 2214. Corkscrew through-hole 2220 maybe configured to receive corkscrew rod 2228 and threaded through-hole2222 may be configured to receive center shaft 2218, which may havecorresponding threading.

Turning each of corkscrew rod 2228 and center shaft 2218 clockwise maycause them to advance relative to the respective through-holes 2220 and2222. That is, when a user turns corkscrew rod grip 2216 clockwise,corkscrew rod 2228 advances through corkscrew through-hole 2220. Whenthe user turns center shaft 2218 clockwise, center shaft 2218 advancesthrough threaded through-hole 2222. Pitch of the corkscrew turns and rodthreading may be designed so that the corkscrew advances more slowly,more quickly, or at the same rate as the center shaft 2218 for a givenrate of rotation.

One feature of threaded cap 2214 is that is allows a user to turn centershaft 2218 and corkscrew rod 2228 independently of each other. The usermay advance or retract them using a drill with the drill's chuckattached to one or both of corkscrew rod grip 2216 and/or center shaft2218. This embodiment is only one example of these mechanisms and theirapplication and those of ordinary skill in the art would recognize otherways without departing from the principles of this disclosure. There maybe similar corkscrew and threaded rod mechanisms that controlindependent advancement of device portions such as screwdrivers, drills,taps, retractors, awls or cutting tools.

FIG. 24 illustrates center shaft 2218, corkscrew rod grip 2216 andcorkscrew rod 2228 in greater detail. Corkscrew rod 2228 is mounted tocorkscrew rod grip 2216 by welding, pinning, or other rigid orsemi-rigid method. Center shaft 2218 may be configured to freely rotateand slide within corkscrew rod grip 2216. To this end, corkscrew rodgrip 2216 may be unthreaded through its center to allow for motion ofcenter shaft 2218 relative to corkscrew rod 2228 and corkscrew rod grip2216.

A chuck of a drill may attach to center shaft 2218 at or near a proximalend (top of center shaft 2218 in FIG. 24) in order to advance centershaft 2218. The same or different chuck may also attach to corkscrew rodgrip 2216 in order to advance corkscrew rod 2228. A cannulated drill andchuck are attached to corkscrew rod grip 2216, thereby allowingcorkscrew rod grip 2216, corkscrew rod 2228, drill and chuck to advancerelative to threaded cap 2214 and center shaft 2218 when the drill isactivated. The chuck and drill attached to center shaft 2218 may beeither cannulated or non-cannulated. When the proximal end of centershaft 2218 is held in the drill chuck and the drill is activated, centershaft 2218, drill and chuck advance relative to threaded cap 2214,corkscrew rod grip 2216 and corkscrew rod 2228 and can be advanced tothe point where the chuck collides with corkscrew rod grip 2216.

FIGS. 25A and 25B illustrate the operation of corkscrew rod 2228. FIGS.25A and 25B do not depict center shaft 2218. FIG. 25A shows corkscrewrod 2228 and inner dilator 2206 in a retracted position and FIG. 25Bshows inner dilator 2206 advanced due to rotation and advancement ofcorkscrew rod 2228 through threaded cap 2214 and through-hole 2220. Arotational bearing may be located distal to corkscrew rod 2228. Therotational bearing may allow corkscrew rod 2228 to rotate in a mannerthat does not in turn also rotate inner dilator 2206.

Other embodiments may exist within the principles disclosed hereinincluding but not limited to nested concentric corkscrews like that of adouble helix to advance the mechanisms. Double or other multiples(triple, quadruple, etc.) of helices can be overlaid with a centralthreaded shaft, allowing multiple other conceivable embodimentsconsistent with this application. When using nested helices around acenter shaft, the number of concentric, independently moving pieceswould equal the number of nested helices plus one (center shaft).

FIGS. 26A and 26B illustrate operation of center shaft 2218. FIGS. 26Aand 26B do not depict corkscrew rod 2228. FIG. 26 illustrates themovement of center shaft 2218 as it rotates and moves in through-hole2222. The threaded portion of center shaft 2218, engaged with threadedthrough-hole 2222, forces center shaft 2218 to advance when rotated.Center shaft 2218 may be attached or have an integrated smooth distalportion that is pointed in its tip to penetrate bone.

FIGS. 27A-27D illustrate operation of dilator system 2000 as the outerdilator 2208 progresses over inner dilator 2206 and within outer sleeve2210. In FIG. 27A, outer dilator 2208 is in a fully retracted positionand inner dilator 2206, center shaft 2218, and center tip 2204 are fullyextended. In FIG. 27B, handles 2212 are forced down, which advancesouter dilator 2208. Pressing fully down handles 2212 fully extends outerdilator 2208 as shown in FIG. 27C. In FIG. 27D, handles 2212 may bemoved up. If handles 2212 are designed so that they are separate fromouter dilator 2208, this action may leave outer dilator 2208 in a fullyextended position. If handles 2212 are designed to be connected to orintegral with outer dilator 2208, this action would return the outerdilator to the position of FIG. 27A. A latching mechanism could beincorporated so that the outer dilator 2208 can be either attached to ordetached from the handles 2212 according to user preference. Operationof outer dilator 2208 using handles 2212 allows the inner tools (e.g.,inner dilator 2206 and center pin 2204) to continue operating asrotating and/or sliding entities, together or independently.

FIGS. 28A-28C illustrate advancement of center pin 2204, inner dilator2206, and outer dilator 2208. In FIG. 28A center pin 2204 is advancedby, for example, rotating center shaft 2218 until center pin 2204engages bone. In FIG. 28B, inner dilator 2206 is advanced by rotating,for example, corkscrew rod 2228. In FIG. 28C, outer dilator 2208 isadvanced by, for example, pushing down on handles 2212 as describedabove.

By incorporating multiple threaded, sliding and rotational mechanisms inthe dilator as disclosed may allow for the independent or simultaneousoperation of two or more tools or sections of a tool when necessary,giving the surgeon enhanced precise control. Similarly, thecorresponding threads on the screwdriver tool and guide tube allow forgreater control during drilling, awling, puncturing or driving, whilealso delivering more power by utilizing the end-effector momentum tohelp drive the screws or tools down. The threaded drive and roboticallycontrolled mechanisms may avoid stripping and aid screws to catch intothe bone along the threads.

Although the robot and associated systems described herein are generallydescribed with reference to spine applications, it is also contemplatedthat the robot system is configured for use in other surgicalapplications, including but not limited to, surgeries in trauma or otherorthopedic applications (such as the placement of intramedullary nails,plates, and the like), cranial, neuro, cardiothoracic, vascular,colorectal, oncological, dental, and other surgical operations andprocedures.

Although several embodiments of the invention have been disclosed in theforegoing specification, it is understood that many modifications andother embodiments of the invention will come to mind to which theinvention pertains, having the benefit of the teaching presented in theforegoing description and associated drawings. It is thus understoodthat the invention is not limited to the specific embodiments disclosedhereinabove, and that many modifications and other embodiments areintended to be included within the scope of the appended claims. It isfurther envisioned that features from one embodiment may be combined orused with the features from a different embodiment described herein.Moreover, although specific terms are employed herein, as well as in theclaims which follow, they are used only in a generic and descriptivesense, and not for the purposes of limiting the described invention, northe claims which follow. The entire disclosure of each patent andpublication cited herein is incorporated by reference in its entirety,as if each such patent or publication were individually incorporated byreference herein. Various features and advantages of the invention areset forth in the following claims.

What is claimed is:
 1. A surgical robot system comprising: a robothaving a robot base, a robot arm coupled to the robot base, anend-effector coupled to the robot arm, a guide tube coupled to theend-effector, and a surgical instrument coupled to the guide tube,wherein the robot is configured to control movement of the end-effectorto perform a given surgical procedure, wherein the guide tube has aninternal threading and the surgical instrument has an external threadingconfigured to engage the internal threading, and wherein the surgicalinstrument is configured to engage a surgical implant while threadablyengaged with the guide tube.
 2. The system of claim 1, wherein thesurgical instrument is a screw driver.
 3. The system of claim 2, whereinthe surgical implant is a screw.
 4. The system of claim 1, wherein therobot is configured to install a polyaxial screw.
 5. The system of claim1, wherein the robot performs orthopedic operations.
 6. The system ofclaim 1, wherein the robot performs surgical operations on the spine. 7.The system of claim 1, wherein the robot performs operations in trauma.8. The system of claim 1, wherein the end-effector is configured tomaintain a position such that a driving force is applied to the surgicalimplant by the surgical tool.
 9. The system of claim 1, wherein theinternal threads and external threads match a pitch of threads on thesurgical implant.
 10. The system of claim 1, wherein the surgical toolis configured to move within the external threading along a longitudinalaxis of the guide tube.
 11. A system for independently advancingmultiple components of a tool into bone, comprising: a center shankconfigured to advance a first component of the tool into a bone, whereinthe center shank is threaded; a rod disposed around the center shank andconfigured to advance a second component of the tool in the bone,wherein the rod is configured to move independently from the centershank.
 12. The system of claim 11, wherein the system is mounted to asurgical robot, the first component is a center pin, and the secondcomponent is an inner dilator.
 13. The system of claim 12, furthercomprising an outer sleeve and an outer dilator, wherein the centershank, the rod, the inner dilator, and the outer dilator are disposedwithin the outer sleeve, and wherein the inner dilator is configured toadvance over the center pin and the outer dilator is configured toadvance over the inner dilator.
 14. The system of claim 13, furthercomprising at least one handle configured to advance the outer dilatorover the inner dilator.
 15. The system of claim 12, wherein the centerpin is configured to have a pointy distal end to engage the bone, andwherein the rod is corkscrew shaped and helically disposed around thecenter shank.
 16. The system of claim 12, wherein the inner dilator isrestricted from rotating as rod advances the inner dilator.
 17. Thesystem of claim 12, further comprising a threaded cap.
 18. The dilatorsystem of claim 17, wherein the threaded cap has a corkscrew shapedthrough-hole configured to receive the rod and a threaded through-holeconfigured to receive the central shaft.
 19. The system of claim 12,wherein the robot is configured to position the system relative to apatient.
 20. The system of claim 19, further comprising a plurality ofhelical rods disposed around the center shank and configured toindependently rotate as nested helices, each helical rod configured toadvance a different component of the tool into a patient.